CN-121996873-A - Pose recognition method, compensation correction control method and system for movable beam of hydraulic machine

CN121996873ACN 121996873 ACN121996873 ACN 121996873ACN-121996873-A

Abstract

The invention relates to the technical field of hydraulic forming, and discloses a pose recognition method, a compensation correction control method and a system of a movable beam of a hydraulic machine. The method is applied to a hydraulic machine pose recognition and compensation system and comprises a movable beam, a main cylinder and four hydraulic compensation cylinders, wherein after the movable beam starts to descend, the method calculates the pressure mutation time difference of the diagonal hydraulic compensation cylinders, the first contact in the diagonal is used as a reference cylinder, the displacement of piston rods of the main cylinder and the reference cylinder in the corresponding time difference is collected, the inclination angle of the movable beam along the diagonal direction is calculated, the pose state of the movable beam is recognized, so that the position compensation quantity is calculated to carry out safety judgment, and if the maximum inclination value is within a preset threshold value, the control parameter of the next forming period is calculated according to the position compensation quantity, and compensation correction control is carried out on the movable beam. The invention can quickly identify the inclination condition of the movable beam, correct the non-synchronous pose of the movable beam, reduce the impact vibration of the movable beam caused by initial inclination and improve the precision of the subsequent leveling stage.

Inventors

HUANG HAIHONG
Guo Xuepu
LI LEI
XU YUHANG
JIN RUI
LI YUSHU

Assignees

合肥工业大学

Dates

Publication Date: 20260508
Application Date: 20260127

Claims (10)

1. The pose recognition method of the movable beam of the hydraulic machine is characterized by being applied to a pose recognition compensation system of the hydraulic machine, the system comprises the movable beam, a main cylinder which is arranged at the center of the upper surface of the movable beam and used for driving the movable beam to descend, and four hydraulic compensation cylinders which are used for supporting the movable beam and adjusting the pose of the movable beam in the descending process of the movable beam, wherein the four hydraulic compensation cylinders are distributed below four corners of the movable beam and symmetrically distributed relative to the center of the movable beam and are in a separated state with the movable beam before descending, and the pose recognition method comprises the following steps: S1, after a movable beam starts to descend, collecting lower cavity pressure of a hydraulic compensation cylinder in real time, respectively recording lower cavity pressure mutation time when the movable beam is in contact with four hydraulic compensation cylinders, and calculating pressure mutation time difference of the diagonal hydraulic compensation cylinders; s2, taking a person, which is in contact with the movable beam, in the diagonal hydraulic compensation cylinder as a reference cylinder, respectively collecting the displacement of piston rods of the main cylinder and the reference cylinder in corresponding pressure abrupt change time differences, and calculating the inclination angle of the movable beam along the diagonal direction; and S3, calculating the inclination angles of the movable beam along the x axis and the y axis of the horizontal plane coordinate system according to the inclination angle of the movable beam along the diagonal direction, namely identifying the pose state of the movable beam.
2. The method for recognizing the pose of a movable beam of a hydraulic machine according to claim 1, wherein in the step S1, a calculation formula of a pressure abrupt change time difference of a diagonal hydraulic compensation cylinder is: in the formula, 、、 And The lower cavity pressure mutation time of the hydraulic compensation cylinders No. 1, no. 2, no. 3 and No. 4 are sequentially provided, To compensate for the abrupt pressure difference between cylinders 1 and 3, Compensating for a sudden pressure difference in time between cylinders No. 2 and No. 4 for the diagonal hydraulic pressure; in the step S2, the contact of the diagonal hydraulic compensating cylinders 1 and 3 with the movable beam is used as a reference cylinder, and the two cylinders are arranged in the following way Piston rod displacement of internal acquisition reference cylinder Displacement of piston rod of master cylinder And a relative displacement coordinate system of the movable beam relative to the piston rod of the reference cylinder is established to obtain the displacement difference between the main cylinder and the reference cylinder And the inclination angle of the movable beam along the radian of the No. 1 hydraulic compensation cylinder and the No. 3 hydraulic compensation cylinder in the diagonal direction is approximately regarded as the chord length Wherein The length of the movable beam is defined as the length of the diagonal line of the movable beam Wide as Then ; The contact of the diagonal hydraulic compensating cylinders No. 2 and No. 4 with the movable beam is used as a reference cylinder, and the two cylinders are arranged in the cylinder Piston rod displacement of internal acquisition reference cylinder Displacement of piston rod of master cylinder And a relative displacement coordinate system of the movable beam relative to the piston rod of the reference cylinder is established to obtain the displacement difference between the main cylinder and the reference cylinder And the inclination angle of the movable beam along the radian of the diagonal direction of the No.2 hydraulic compensation cylinder and the No. 4 hydraulic compensation cylinder is approximately regarded as the chord length 。
3. The method for recognizing the pose of the movable beam of the hydraulic machine according to claim 2, wherein in the step S3, the calculation formula of the inclination angle of the movable beam in the radian system of the x-axis and the y-axis of the horizontal plane coordinate system is: in the formula, The inclination angle of the movable beam along the x axis; is the inclination angle of the movable beam along the y axis.
4. The method for recognizing the pose of the movable beam of a hydraulic machine according to claim 3, wherein in step S3, the position compensation values of the four hydraulic compensation cylinders are also obtained by the following formula: In the method, the first contact cylinder of the four hydraulic compensation cylinders, which is the first contact with the movable beam, The compensation value is the position of the first contact cylinder; A hydraulic compensating cylinder position compensation value along the x-axis direction of the first contact cylinder; a hydraulic compensating cylinder position compensation value along the y-axis direction of the first contact cylinder; And compensating the position compensation value of the hydraulic compensating cylinder positioned in the diagonal direction of the first contact cylinder.
5. The compensation correction control method for the movable beam of the hydraulic machine is applied to a pose recognition compensation system of the hydraulic machine, and the system comprises the movable beam, a main cylinder which is arranged in the center of the upper surface of the movable beam and is used for driving the movable beam to descend, and four hydraulic compensation cylinders which are used for supporting the movable beam and adjusting the pose of the movable beam in the descending process of the movable beam, wherein the four hydraulic compensation cylinders are distributed below four corners of the movable beam and are symmetrically distributed relative to the center of the movable beam and are in a separated state with the movable beam before descending, and is characterized by comprising the following steps: Step one, initializing a pose recognition compensation system before the forming work of a hydraulic press starts, and initializing a forming period counter as The speed feedback control quantity of four hydraulic compensation cylinders in the pre-adjustment stage Feedforward compensation voltage Initializing to 0 and extending the piston rod of the hydraulic compensating cylinder to the position Initialization to return stage system initial extended position Wherein , Time is; step two: the hydraulic machine starts to work, controlling piston rod of hydraulic compensation cylinder according to Extend to the appointed butt joint position to make Entering a forming stage; step three, in the forming process, adopting the pose recognition method as claimed in claim 4 to recognize the pose state of the movable beam and obtain the position compensation quantity of each hydraulic compensation cylinder ; Step four, four position compensation amounts are calculated Maximum value of (a) or (b) the maximum inclination of the movable beam And a preset maximum tilt threshold Comparing if According to the position compensation amount Calculating control parameters of the next forming cycle including the piston rod extension position Speed feedback control amount in pre-adjustment stage Feedforward compensation voltage ; Step five, entering a pre-adjustment stage, and feeding back the control quantity according to the speed obtained in the previous forming period Feedforward compensation voltage Performing compensation control, and adjusting the speeds of piston rods of the four hydraulic compensation cylinders to enable the movable beam to recover to the level before the leveling stage; Step six, entering a leveling stage, and returning to the step two after finishing the forming.
6. The compensation and correction control method for movable beam of hydraulic machine according to claim 5, wherein in the fourth step, if And sending out a safety alarm, stopping the machine by itself and outputting the pose state of the movable beam.
7. The pose recognition and compensation system of the hydraulic machine is characterized by comprising a movable beam, a main cylinder which is arranged in the center of the upper surface of the movable beam and used for driving the movable beam to descend, and four hydraulic compensation cylinders which are used for supporting the movable beam and adjusting the pose of the movable beam in the descending process of the movable beam, wherein the four hydraulic compensation cylinders are distributed below four corners of the movable beam and are symmetrically distributed relative to the center of the movable beam and are in a separated state with the movable beam before descending, and the pose recognition and compensation system further comprises a controller which is used for executing the compensation and correction control method of claim 5 and realizing compensation and correction control of the movable beam.
8. The system of claim 7, further comprising a monitoring unit including displacement sensors disposed on the master cylinder and the four hydraulic compensation cylinders for acquiring the displacement of the piston rod of the corresponding cylinder.
9. The system of claim 8, wherein the monitoring unit further comprises pressure sensors disposed on the four hydraulic compensation cylinders for collecting hydraulic oil pressure in the lower chamber of the cylinder.
10. The system of claim 7, further comprising a servo valve for controlling the flow and direction of hydraulic oil in the hydraulic compensating cylinder and a source of oil for supplying oil to the hydraulic machine.

Description

Pose recognition method, compensation correction control method and system for movable beam of hydraulic machine Technical Field The invention relates to the technical field of hydraulic forming, in particular to a pose recognition method, a compensation correction control method and a compensation correction control system for a movable beam of a hydraulic machine. Background In the hydroforming process, the movable beam is used as a key component for bearing the upper die and transmitting load to the workpiece, and the pose state of the movable beam is directly related to the forming quality of the workpiece and the service lives of the die and the whole machine. When the movable beam cannot maintain an ideal parallel posture in the descending process, obvious differences can occur in four-angle stress, larger impact load can be generated in the butt joint process, and damage to the guide rail, the cylinder body and the die is induced. Therefore, the pose of the movable beam is accurately identified before the hydroforming stage, and timely and reasonable adjustment and compensation control are implemented on the basis of the pose, so that the method has important significance for guaranteeing the safe operation of equipment and guaranteeing the quality of products. The existing hydraulic machine usually adopts a mode of combining manual measurement with empirical adjustment to manually correct the posture of the movable beam when the movable beam is initially inclined, and usually needs to use tools such as a level meter to measure four corners and connection positions of the movable beam in a stop state, and then realizes the posture adjustment of the movable beam through adjusting gaskets, connecting rods or fasteners and the like. The method not only depends on experience of operators, but also is difficult to ensure repeatability and accuracy, and has long debugging period, thus delaying production rhythm. Although some equipment is provided with a four-corner leveling pose recognition and compensation system, the system is mainly aimed at simple synchronization based on the displacement or pressure of a leveling cylinder in the compression forming stage, and lacks of unified description and on-line recognition means for the integral pose of the movable beam. Therefore, the safety judgment and the compensation control on the position and the posture state of the movable beam based on the cylinder data obtained in the butt joint stage are researched, the real-time monitoring and the safety judgment on the position and the posture of the movable beam can be realized under the condition of not interrupting production, and the automation degree and the safety of the hydraulic position and posture recognition compensation system are improved. Disclosure of Invention In order to solve the technical problems in the prior art, the invention provides a pose recognition method, a compensation correction control method and a system for a movable beam of a hydraulic machine, which aim to rapidly recognize the inclination condition of the movable beam and correct the asynchronous butt joint situation pose of the movable beam, so that impact oscillation of the movable beam caused by initial inclination is reduced, and the precision of a subsequent leveling stage is improved. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention discloses a pose recognition method of a movable beam of a hydraulic machine, which is applied to a pose recognition compensation system of the hydraulic machine, and the system comprises the movable beam, a main cylinder which is arranged at the center of the upper surface of the movable beam and is used for driving the movable beam to descend, and four hydraulic compensation cylinders which are used for supporting the movable beam and adjusting the pose of the movable beam in the descending process of the movable beam, wherein the four hydraulic compensation cylinders are distributed below four corners of the movable beam and are symmetrically distributed relative to the center of the movable beam and are in a separated state with the movable beam before descending, and the pose recognition method comprises the following steps: S1, after a movable beam starts to descend, collecting lower cavity pressure of a hydraulic compensation cylinder in real time, respectively recording lower cavity pressure mutation time when the movable beam is in contact with four hydraulic compensation cylinders, and calculating pressure mutation time difference of the diagonal hydraulic compensation cylinders; s2, taking a person, which is in contact with the movable beam, in the diagonal hydraulic compensation cylinder as a reference cylinder, respectively collecting the displacement of piston rods of the main cylinder and the reference cylinder in corresponding pressure abrupt change time differences, and calculating the inclination angle of the